The oldest living plant in the world isn't that bristle cone pine in Nevada or that huckleberry in Pennsylvania.
It's a colony of King's Holly found in the Tasmanian rain forest.
The King's Holly plant is a triploid. It has three sets of chromosomes instead of two. This makes the plant incapable of producing flowers and viable seeds. Because of this it is unable to sexually reproduce. Instead, the plants produces clones of itself by sending out root suckers, dropping identical copies of itself within the boundaries of it's habitat.
Using a nearby fossil of an identical plant, researchers estimate that the King's Holly is over 43,000 years old.
The exact location of the colony is a closely guarded secret as it is the only living example of King's Holly.
There are other supergeriatric plants around the world. One creosote plant in California is approximately 11,700 years old. Creosote bushes can reproduce sexually but also vegetatively. Creosote bushes require summer rains for successful sexual reproduction. When rainfall is rare, creosote bushes send out clones in a widening circle while the original plant dies back.
Certain Antarctic lichens are estimated to be about 10,000 years old. Cructose lichen, being comprised of two entities, a fungus and an algae that live in a symbiotic relationship, can't reproduce sexually either. Lichen also reproduce vegetatively and even more slowly than the King's Holly.